1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device which can prevent corrosion of a terminal portion thus enhancing reliability of the liquid crystal display device.
2. Description of Related Art
For example, as described in following patent document 1 or the like, a transflective liquid crystal display device which includes a transmissive portion and a reflective portion within one sub pixel has been used as a display of portable equipment.
In such a transflective liquid crystal display device, a semiconductor chip which constitutes a drive circuit is mounted on one glass substrate which constitutes a liquid crystal display panel in a COG method. That is, bump electrodes of the semiconductor chip are electrically and mechanically connected to a terminal portion (pad electrode) formed on the glass substrate.
FIG. 8 is a cross-sectional view for explaining the constitution of a terminal portion of a conventional transflective liquid crystal display device. As shown in FIG. 8, the conventional terminal portion includes a lower electrode portion (TL) which is formed on a glass substrate (SUB1), and an upper electrode portion (TH) which is formed on the lower electrode portion (TL) and is electrically connected with the lower electrode portion (TL).
Further, the lower electrode portion (TL) is covered with an insulation film (PAST) having an opening portion (CHT) through which a portion of the lower electrode portion (TL) is exposed, and the upper electrode portion (TH) is formed on the insulation film (PAST) and is electrically connected with the lower electrode portion (TL) at an opening portion which is formed in the insulation film (PAST).
Here, the lower electrode portion (TL) is, for example, formed of a metal film made of aluminum (Al) or the like, or an alloy film made of AlNd (neodymium) or the like, while the upper electrode portion (TH) is formed of an amorphous ITO film.